Question: $ 49^{-\frac{1}{2}}$
Answer: $= \left(\dfrac{1}{49}\right)^{\frac{1}{2}}$ Figure out what goes in the blank: $\Big(? \Big)^{2}=\dfrac{1}{49}$ Figure out what goes in the blank: $\Big({\dfrac{1}{7}}\Big)^{2}=\dfrac{1}{49}$ So $49^{-\frac{1}{2}}=\left(\dfrac{1}{49}\right)^{\frac{1}{2}}=\dfrac{1}{7}$